Many audio systems today have “phone connectors” (frequently also called “plugs”) to permit connection of headphones, headsets, microphones, etc. There are currently three standard diameters: 6.35 mm (¼″), 3.5 mm (⅛″), and 2.5 mm ( 3/32″). There also are currently three generally accepted tap arrangements. Two-tap phone connectors (often also called “monophone plugs”) can be used for mono audio devices. These are increasingly uncommon. Three-tap phone connectors (often also called “stereophone plugs”) can be used for stereo devices or simpler combination devices (e.g., earplug and microphone headsets). These are presently the most commonly encountered type. Of present interest, however, standardized four tap phone connectors which are becoming increasingly important. These are also called “combo connectors” and that term is used herein. There are also various non-standard connectors, but these are often undesirable to many system designers and especially to consumers, for reasons discussed presently. When a standard connector can be specified in place of a non-standard one, most audio designers will do so.
FIG. 1 (prior art) is a schematic diagram of how a conventional three-tap phone connector can be employed in a stereo headphone application. The diameter of the phone connector used here would typically be 3.5 mm (⅛″), especially if the audio system is portable. A 6.35 mm (¼″) phone connector might also be used, say, if the audio system is a stationary home or studio system, or one used in a theater or nightclub. [Connector diameter is not relevant to the present invention and its frequent mention herein is merely for completeness and to establish context with what is standard in the industry.]
FIG. 2 (prior art) is a schematic diagram of how a conventional three-tap phone connector can be employed in a cellular telephone headset application. The diameter of the phone connector used for this today is typically 2.5 mm ( 3/32″). That tends to frustrate sometimes consumers, who may encounter situations where an adapter is required to employ a 3.5 mm (⅛″) connector in a 6.35 mm (¼″) jack, and who may resent having additional devices that are incompatible without an adapter.
FIG. 3 (prior art) is a schematic diagram of how a conventional combo phone connector can be employed in a stereo headphone and microphone application (e.g., a karaoke system). There is presently no official standard for a microphone connection, but the system shown here is a straightforward extension of what is shown in FIG. 2 and is widely used.
Both of the applications in FIG. 2 and FIG. 3 include mute buttons or, more generically, a single control capability. Having any control capabilities in an external device of an audio system can be very useful, especially if these amount to more than just a mute capability. For example, in a karaoke system the user-performer would usually like to have accessible volume-up and volume-down buttons in additional to a mute, and in a more formal entertainment system it might be desirable to also have lights-up and lights-down buttons. Similarly, in a personal or wearable multi-media player it is clearly desirable to have buttons or switches for mute, volume-up, volume-down, next-selection, last-selection, etc.
Of course, such controls are typically provided at the main audio device itself, but those are often very inconvenient for users. For instance, a karaoke user-performer that is already wearing a headphone and holding a microphone should not have to walk over to a console just to reduce the volume one step. Similarly, the user of a multi-media player should not have to reach into their pocket or backpack and pull out their device just to change selections or volume.
This need for additional remote control capabilities has long been appreciated and various solutions have been attempted. One approach has been to use additional jacks on the main audio system and then use additional connectors and cables for the external devices. Having additional connectors and cables, however, is usually not desirable. The more typical approach, therefore, has been to use a non-standard connector with additional taps. Due to the number of taps needed, many such non-standard connectors use a multi-pin plug instead of the accepted cylindrical or barrel shape of the conventional phone connector. Frequently such plugs also have a “polarized” shape to prevent incorrect socket insertion.
Non-standard connectors are almost universally hated by audio system users, and are a major source of service and customer support issues for audio system manufactures. It is thus widely accepted that the use of non-standard connectors is not an adequate solution to the growing need for additional remote system control capabilities.
Accordingly, what is needed is a way to provide multiple, i.e., at least two, external control capabilities for audio systems yet also stay within the confines of current industry standards.